Object Oriented Programming

5. Operation and maintenance Normally (although not necessarily), this is the longest life cycle phase. The system is installed and put into practical use. Maintenance involves correcting errors which were not discovered in earlier stages of the life cycle, improving the implementation of system units and enhancing the system’s services as new requirements are discovered.

Waterfall model
Requirements
Definition
System and
Software Design
Implementation
and Unit Testing
Integration and
System Testing
Operation and
Maintenance
Waterfall model

• Incremental development is based on the idea of developing an initial implementation, exposing this to user comment and evolving it through several versions until an adequate system has been developed.
• Specification, development, and validation activities are interleaved rather than separate, with rapid feedback across activities.
• Incremental software development, which is a fundamental part of agile approaches, is better than a waterfall approach for most business, e-commerce, and personal systems.

Incremental development

• Incremental development reflects the way that we solve problems.
• We rarely work out a complete problem solution in advance but move toward a solution in a series of steps, backtracking when we realize that we have made a mistake.
• By developing the software incrementally, it is cheaper and easier to make changes in the software as it is being developed.

Incremental development

• Each increment or version of the system incorporates some of the functionality that is needed by the customer.
• The customer can evaluate the system at a relatively early stage in the development to see if it delivers what is required. If not, then only the current increment has to be changed and new functionality defined for later increments

Incremental development